Signal system



J. NELSON SIGNAL SYSTEM Feb. 21, 192s.

Filed lJuly lO, 1925 www@ - is associated with the motor 'on line 2 2 ofFig. 1;

Reemer! Feb. 21, 192s.

UNITED STATES JENNINGS 1\T.'ilIS0N,l 0F CHICAGO, ILLINOIS.

SIGNAL SYSTEM. l

Application filed July 10, 1925. Serial No. 42,631.

This invention relates to a signal system which may be used withparticular advantage in the operation of an automobile. It

lubricating system, and includes in its assembly an indicator which maybe located close to.` the operator.

A primary purpose of the present signal system is to convey a warning'whenever there is a Jfailure of oil pressure. Foi` safe operation,'acertain pressure should be maintained in the lubricating system of anymotor. If the pressure, therefore, falls below a safety limit, or ceasesaltogether, the operator should be warned immediately so that the motormay be stopped to thereby avoid injury to its moving parts. The signalsystem of my invention is accordingly designed to afford an indicationof any such changes in oil pressure conditions as call for an iinmediateshutting down of the power plant.

A preierred embodiment o my invention is shown in the accompanying.drawing in the manner following:

Figure 1 is a central vertical section through the switch component; 'i

Fig. 2 is a transverse secion therethrough Fig. 3 is a layout of theentire system including the electrical connections which eX- tendbetween its component units.

The switch A shown in Fig. 1 includes a tubularhousing vwhereinis avertically disposed cylindrical chamber 4. An inlet 5 to the chamber issomewhat higher elevation. In connection with the inlet is a pipe 7 towhich oilis delivered from a pump B, a second pipe 8 extending from theoutlet `6 to deliver 'oil to the Vvarious points desired.v The pump isconnected with a motorf(not shown) so as to be driven thereby to furnisha circulation of oil to its several bearings, etc.-

Slidably tted within the chamber 4 is a plunger 9. Under conditions oflittle or no pressure, the plunger will drop sothat its lower end isrested upon a cross bolt 101 .which extends transversely through thebolt assembly is such that the two bushings' lThe conductor 19 is alsovtem is as follows: With provided near the lower endy thereofas is alsoan outlet 6 at a point of signal is inactive,

are held snugly .within their seats to make an oil-tight tit, when thenut is I'tightened upon the bolt. When the plunger is rested against thebolt, the circuit is, vof course, oompleted to the ground.

The upper end of the housing which is open is threaded to receive aclosure cap15 which is fitted with the aid of a gasket 16 `so as torender .this connection oil-tight. Within the closure cap is a chamber17 eX- tending above the upper end of the housing so as to communicatewith a by-pass 18 which extends vertically through the housing wall toconnect with' the outlet 6.

The conductor 14 leads to a signal device C whichmay conveniently be alamp, buzzer, or the like.' From this'si al a-connection 19 is carriedto one pole ogg motor ignition switch D. From its other pole a conductor20 leads to a source of electrical energy E. in connection with anignition coil F. A'wiring diagram in which the above describedconnections are contained is set forth in Fig. 3, and is suggested asone which is suitable for the purpose of this invention. t

The operation of the present signal sysclosing of the ignition switch, acircuit is completed through the si al C and switch A to the groundwhere y the signal is set in operation. As soon as the motor is runningunder-its own power, however, the pump B sends oil under Y pressurethrough the pipe 7 to lift the plunger 9, thereby opening the switch.The plunger may rise inthe housing to about the height indicated bydotted lines in Fig. 1, where a passage is cleared for the circulationof oil through' to the outlet 6. The plunger remain-"in this positionindefinitely, that is, as long as the oil pump continues to function.While so elevated, the thus indicating the proper functioning of 'the'oil system.

If, for any reason, whether through failure of the` pump, insuiiicientoil, or otherwise, the pressure should fall below the amount requisitefor the continued suspension of the plunger, the circuit through theconductor 14. willbe reestablished tooperate the signal. The warningthus given is informaltive of a change in conditions which calls sovsignal system will perform a useful service, as, for example, when theoperator prepares to leave the car in the belief that the ignitionswitch is turned'oif when .the engine is stopped. Should this not be thecase, the signal'will be operating, thus warning him that current isstill passing through the ignition coil. Likewise should'the operatorstop his automobile, where there is considerable noiseabout him, hisengine might stop without his being aware of that fact. With the presentsignal system, however, this could not happen,- because the operatorwould be warned at once of the true conditions.

It will be noted that the present/switch A. comprises but onemoving-part, namely, the

L, plunger 9. As the surfaces against which itv moves are constantlyiushed with oil, it requires no lubrication on its own account..

Should there'be a slight leaka e of oil, past the upper end oftheplunger, t is will be returned tothe outlet 6 through the by-pass 18. Iprefer that the movement of the plunger should be in afverticaldirection so 'as to utilize the force ofgr'avit'y rather than a springto oppose the oil pressure which is exertedupon the under side of theplunger.

` rlhis makes for simplicity and economy and also for greater durabilityin the structure. The cross bolt l2 withY which the plunger makeselectrical contact serves also' as a stop 4which limits downwardmovement of the plunger to a pointwhere oil is always permitted to enterthe chamber 4 -through the inlet 5 to exert an upward pressure on theplunger. By combining and' arran "ng the parts in the manner described,il redgiice to a minimum the numberlof elements which are necessary inthe operation of the present device. lt may, of course, be variouslymodi tied, but inso far as such changes respond to theA terms of the lapnded claims, l would include them allwithin the scope of this chamber toopen or close the outlet in response i,

to variations in pressure of oil entering through thelinlet, and meansengagedhy the plunger when closing the outlet to establish' anelectrical circuit, substantially .as described.

2. ln a pipeline, an interposed housing having a chamber through whichHuid is circulated, there being inlet and outlet connections to thehousing chamber, a bolt extending throughvthe housing with its oppositeends disposed exteriorly thereof, a pair of bushings formingmountingsfor the bolt and each seated within. an opening in the housing walls, ahead on one end of the bolt, a nut screw threaded on the other bolt endand adapted, when tightened to hold the two bushings closely withintheir seats in a manner whereby leakage of oil is prevented, and

means movable within the housing chamber in response to variations inVHuid pressure A adapted with failure in such pressure to con^ tact withthe bolt wherebyianelectrical circuit is completed, substantiallyasdescribed# Qiniviiiivcfs itntsoii.

